Gwenda Blair, the author of The Trumps: Three Generations That Built An Empire, told Inside Edition that hiding your heritage in the era of World War II was not unheard of.

“In the 1940s, people, especially in the real estate industry in New York, didn't want to hear that somebody was German — so let's get rid of that. Let's be Swedish,” Blair said.

The book claims Donald’s father, Fred, told colleagues and constituents that his family was Swedish, not German, and Trump ran with it, even keeping up the fiction as late at 1987 in his best seller Trump: The Art of the Deal.

According to the New York Times, Donald was curious as to why he had to claim the family was Swedish when he was working on Art of the Deal, reportedly asking his dad: "Do I have to do this Swedish thing?"

The Trump family has roots in the quaint village of Kallstadt, Germany. Trump’s grandfather, Fredrick Sr., was born in a modest home and married the woman who lived across the street from him.

Frederick Trump, Sr. and his wife, Elizabeth, left Germany in 1905 and settled in Queens, New York.

"Trump" wasn't always the family name, as comedian John Oliver revealed in May on Last Week Tonight. The Trumps were known as "Drumpfs" in the 1500s.

Subsequent generations changed the name to “Trum,” then “Tromb,” “Drumb” and finally “Trump.

The family company, Elizabeth Trump and Son, made it big when they began building single family homes in Queens. Fred Jr. and his wife, Mary Anne, would settle in the borough, giving birth to Donald and his 4 siblings.